scholarly journals Unveiling the X-ray broad band continuum and iron line complex on Mkn 841

2007 ◽  
Author(s):  
Pierre-Olivier Petrucci ◽  
G. Ponti ◽  
G. Matt ◽  
A. Longinotti ◽  
M. Mouchet ◽  
...  
Keyword(s):  
Broad Band ◽  
Iron Line ◽  
X Ray ◽  
Line Complex

scholarly journals Unveiling the broad band X-ray continuum and iron line complex in Mrk 841

2007 ◽  
Vol 470 (3) ◽  
pp. 889-902 ◽  
Author(s):  
P. O. Petrucci ◽  
G. Ponti ◽  
G. Matt ◽  
A. L. Longinotti ◽  
J. Malzac ◽  
...  
Keyword(s):  
Broad Band ◽  
Iron Line ◽  
X Ray ◽  
Line Complex

Broad Band X-Ray Telescope observations of NGC 4151 - Iron line diagnostics

1992 ◽  
Vol 401 ◽  
pp. L11 ◽  
Author(s):  
K. A. Weaver ◽  
R. F. Mushotzky ◽  
K. A. Arnaud ◽  
P. J. Serlemitsos ◽  
F. E. Marshall ◽  
...  
Keyword(s):  
Broad Band ◽  
Iron Line ◽  
X Ray ◽  
Ngc 4151

BeppoSAX observations of the massive X-ray pulsar Cen X-3: Broad-band spectra and iron line diagnostic

2000 ◽  
Vol 25 (3-4) ◽  
pp. 413-416 ◽  
Author(s):  
S. Del Sordo ◽  
D. Dal Fiume ◽  
M. Orlandini ◽  
S. Piraino ◽  
A. Santangelo ◽  
...  
Keyword(s):  
Broad Band ◽  
Iron Line ◽  
X Ray ◽  
Band Spectra

scholarly journals The role of molecular gas in the nuclear regions of IRAS 00183-7111

2018 ◽  
Vol 616 ◽  
pp. A127 ◽  
Author(s):  
I. Ruffa ◽  
C. Vignali ◽  
A. Mignano ◽  
R. Paladino ◽  
K. Iwasawa
Keyword(s):  
Column Density ◽  
Broad Band ◽  
Molecular Gas ◽  
Iron Line ◽  
X Ray ◽  
Diagnostic Diagram ◽  
Ultraluminous Infrared Galaxy ◽  
High Ionization ◽  
Nuclear Environment ◽  
Nuclear Regions

Aims. We present a multi-frequency study of the ultraluminous infrared galaxy (ULIRG) IRAS 00183-7111 (z = 0.327), selected from the Spoon diagnostic diagram as a highly obscured active galactic nucleus (AGN) candidate. ALMA millimetre and X-ray observations are used; the main aim is to verify at what level the molecular gas, traced by the CO, may be responsible for the obscuration observed at X-ray energies. Theory and observations both suggest that galaxy-scale absorption may play a role in the AGN obscuration at intermediate (i.e. Compton-thin) column densities. Methods. We calibrated and analysed ALMA archival Cycle 0 data in two bands (Bands 3 and 6). The X-ray properties of IRAS 00183-7111 were studied by reducing and analysing separately archival Chandra and XMM-Newton data; recently acquired NuSTAR spectra were first examined individually and then added to the Chandra and XMM spectra for the broad-band (0.5 − 24 keV, observed frame) analysis. Results. We derived a molecular gas column density of (8.0 ± 0.9) × 1021 cm−2 from the ALMA CO(1−0) detection, while the best-fit column density of cold gas obtained from X-ray spectral fitting is 6.8−1.5+2.1×1022 cm−. The two quantities suggest that the molecular gas may contribute only a fraction of the AGN obscuration; however, the link between them is not straightforward. The nuclear regions of IRAS 00183-7111 are likely stratified into different layers of matter: one inner and highly ionized by the strong radiation field of the AGN (as inferred from the high-ionization iron line found in the X-ray spectra), and one outer and colder, extending more than 5 kpc from the nucleus (as traced by the molecular gas observed with ALMA). The molecular gas regions also give rise to a vigorous starburst with SFR ~260 ± 28 M⊙ yr−1. The complexity of this nuclear environment makes it difficult to identify the origin of the AGN obscuration given the quality of the data currently available. Higher resolution observations in the millimetre regime are needed to deeply investigate this issue.

scholarly journals Recent Satellite Observations of X-ray Emission from AGN

2000 ◽  
Vol 195 ◽  
pp. 77-87
Author(s):  
H. Kunieda
Keyword(s):  
Accretion Disks ◽  
Broad Band ◽  
Satellite Observations ◽  
Spectral Variability ◽  
Edge Structure ◽  
Iron Line ◽  
X Ray ◽  
Central Engine ◽  
Photoionized Plasmas ◽  
Strong Radiation

Recent X-ray satellite observations provide plenty of spectral information with high resolution in a broad band. Major results from the spectral observations are related to the interaction of the power-law continuum flux with the ambient plasmas and accretion disks. The most prominent result is the broad iron-line feature from Seyfert I galaxies which is interpreted as the emission from the relativistic accretion disk. Doppler shift and boosting, as well as gravitational redshifts, are considerable at the distance of several Schwarzschild radii from the central black hole. Strong radiation from the central engine ionizes the ambient material of AGN. Edge structure found at around 0.8 keV is attributed to highly ionized oxygen of O VII and O VIII. Some iron emission lines from Seyfert II galaxies are emitted by highly photoionized plasmas. The study of fast temporal and spectral variability is the key approach to examine the emission mechanism and structure of the central vicinity of AGN. In 2000, two X-ray observatories (Chandra and XMM will be in orbit, and they will provide us with deeper insights of the physics around the black holes and of the physics of hot plasmas.

scholarly journals Detection of a High-Temperature Blackbody Hump in Black Hole Spectra. The strongly redshifted annihilation line

2020 ◽  
Author(s):  
Lev Titarchuk ◽  
Elena Seifina
Keyword(s):  
Black Hole ◽  
High Temperature ◽  
Broad Band ◽  
Spectral Feature ◽  
Line Emission ◽  
Energy Spectra ◽  
Color Temperature ◽  
Iron Line ◽  
Annihilation Line ◽  
X Ray

Abstract We detected a so called high-temperature blackbody (HBB) component, found in the 15 – 40 keV range, in the broad-band X-ray energy spectra of black hole (BH) candidate sources. A detailed study of this spectral feature is presented using data from five of the Galactic BH binaries, Cyg X–1, GX 339–4, GRS 1915+105, SS 433 and V4641 Sgr in the low/hard, intermediate, high/soft and very soft spectral states (LHS, IS, HSS and VSS, respectively) and spectral transitions between them using RXTE, INTEGRAL and BeppoSAX data. In order to fit the broad-band energy spectra of these sources we used an additive XSPEC model, composed of the Comptonization component and the Gaussian line component. In particular, we reveal that the IS spectra have the HBB component which color temperature, kTHBB is in the range of 4.5 – 5.9 keV. This HBB feature has been detected in some spectra of these five sources only in the IS (for the photon index Γ > 1.9) using different X-ray telescopes. We also demonstrate that a timescale of the HBB-feature is of orders of magnitude shorter than the timescale of the iron line and its edge. That leads us to conclude that these spectral features are formed in geometrically different parts of the source and which are not connected to each other. Laurent & Titarchuk (2018) demonstrated a presence of a gravitational redshifted annihilation line emission in a BH using the Monte-Carlo simulations and therefore the observed HBB hump leads us to suggest this feature is a gravitational redshifted annihilation line observed in these black holes.

scholarly journals On the disc reflection spectroscopy of NS LMXB Serpens X-1: analysis of a recent NuSTAR observation

2020 ◽  
Vol 494 (3) ◽  
pp. 3177-3185
Author(s):  
Aditya S Mondal ◽  
G C Dewangan ◽  
B Raychaudhuri
Keyword(s):  
Boundary Layer ◽  
Continuum Model ◽  
Broad Band ◽  
Iron Line ◽  
X Ray ◽  
Reflection Model ◽  
Single Temperature ◽  
Back Scattering ◽  
Low Mass ◽  
Spectral State

ABSTRACT We present NuSTAR observation of the atoll type neutron star (NS) low-mass X-ray binary (LMXB) Serpens X-1 (Ser X-1) performed on 2018 February 17. We observed Ser X-1 in a soft X-ray spectral state with 3–79 keV luminosity of LX ∼ 0.4 × 1038 erg s−1 (${\sim}23{{\ \rm per\ cent}}$ of the Eddington luminosity), assuming a distance of 7.7 kpc. A positive correlation between intensity and hardness ratio suggests that the source was in the banana branch during this observation. The broad-band 3–30 keV NuSTAR energy spectrum can be well described either by a three-component continuum model consisting of a disc blackbody, a single temperature blackbody, and a power law or by a two-component continuum model consisting of a disc blackbody and a Comptonization component. A broad iron line ∼5–8 keV and the Compton back-scattering hump peaking at ∼10–20 keV band are clearly detected in the X-ray spectrum. These features are best interpreted by a self-consistent relativistic reflection model. Fits with relativistically blurred disc reflection model suggests that the inner disc radius Rin is truncated prior to the ISCO at (1.9–2.5) RISCO (${\simeq}11.4\!-\!15\, R_{g}\: \text{or}\: 26\!-\!34$ km) and the accretion disc is viewed at a low inclination of i ≃ 16°−20°. The disc is likely to be truncated either by a boundary layer or by the magnetosphere. Based on the measured flux and the mass accretion rate, the maximum radial extension for the boundary layer is estimated to be ∼6.4 Rg from the NS surface. The truncated inner disc in association with pressure from a magnetic field sets an upper limit of B ≤ 1.9 × 109 G.

scholarly journals AstroSat observations of the first Galactic ULX pulsar Swift J0243.6+6124

2020 ◽  
Vol 500 (1) ◽  
pp. 565-575
Author(s):  
Aru Beri ◽  
Sachindra Naik ◽  
Kulinder Pal Singh ◽  
Gaurava K Jaisawal ◽  
Sudip Bhattacharyya ◽  
...  
Keyword(s):  
Power Law ◽  
Broad Band ◽  
Line Emission ◽  
High Energy ◽  
Emission Feature ◽  
Iron Line ◽  
Strong Function ◽  
X Ray ◽  
Broad Emission ◽  
The Continuum

ABSTRACT Swift J0243.6+6124, the first Galactic ultraluminous X-ray pulsar, was observed during its 2017–2018 outburst with AstroSat at both sub- and super-Eddington levels of accretion with X-ray luminosities of LX ∼ 7 × 1037 and 6 × 1038 erg s−1, respectively. Our broad-band timing and spectral observations show that X-ray pulsations at ${\sim}9.85~\rm {s}$ have been detected up to 150 keV when the source was accreting at the super-Eddington level. The pulse profiles are a strong function of both energy and source luminosity, showing a double-peaked profile with pulse fraction increasing from ∼$10{{{\ \rm per\ cent}}}$ at $1.65~\rm {keV}$ to 40–80 ${{\ \rm per\ cent}}$ at $70~\rm {keV}$. The continuum X-ray spectra are well modelled with a high-energy cut-off power law (Γ ∼ 0.6–0.7) and one or two blackbody components with temperatures of ∼0.35 and $1.2~\rm {keV}$, depending on the accretion level. No iron line emission is observed at sub-Eddington level, while a broad emission feature at around 6.9 keV is observed at the super-Eddington level, along with a blackbody radius ($121\!-\!142~\rm {km}$) that indicates the presence of optically thick outflows.

scholarly journals Broad-band X-ray emission and the reality of the broad iron line from the neutron star–white dwarf X-ray binary 4U 1820−30

2016 ◽  
Vol 461 (2) ◽  
pp. 1917-1926 ◽  
Author(s):  
Aditya S. Mondal ◽  
G. C. Dewangan ◽  
M. Pahari ◽  
R. Misra ◽  
A. K. Kembhavi ◽  
...  
Keyword(s):  
Neutron Star ◽  
White Dwarf ◽  
Broad Band ◽  
Iron Line ◽  
X Ray

Microscintillator of Ce Doped β-NaLuF4 in Uniform Hexagonal Prism Morphology by a Facile Hydrothermal Method

2014 ◽  
Vol 541-542 ◽  
pp. 220-224
Author(s):  
Li Sha Liu ◽  
Hao Hong Chen ◽  
Bi Qiu Liu ◽  
Bin Tang ◽  
Zhi Jia Sun ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hexagonal Phase ◽  
Broad Band ◽  
High Energy ◽  
Hexagonal Prism ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Strong Broad Band ◽  
Broad Band Emission ◽  
Band Emission

To explore micro-or nanoscintillator with a controllable architecture, a novel facile hydrothermal method easy for commercial run was used to synthesize pure and Ce doped β-NaLuF4 microcrystals at 453K. The morphology of uniform hexagonal prism with 3.3μm in diameter and 1.4 μm in thickness, respectively, is presented by the results of scanning electron microscopy (SEM). Powder X-ray diffraction (PXRD) patterns show the products are both pure hexagonal phase. Different from the undoped product without any irradiation, the Ce doped product has given strong broad band emission attributed to 5d4f transition of Ce3+, which can be potentially used as scintillator for biomedical imaging and detectors for high energy such as X-ray and γray. This synthetical strategy extends the understanding about nanomaterial chemistry and can be also useful for other systems such as fluorides, oxides and sulfides.

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